On Thu, Jan 09, 2020 at 03:53:40PM +0100, [email protected] wrote: > Regarding the master CLI: > > On Thu, Jan 09, 2020 at 02:31:19PM +0000, William Dauchy wrote: > > that's a good subject to talk about. While looking at this I also > > wondered why it was not possible to configure it in the config file; to my > > knowledge there is no explanation about it in the doc, nor in the code, > > but I might have missed something. > > I did not know about those concerns around being able to access CLI even > > if the config file is corrupted, thanks for the clarification. > > > > In fact it's supposed to be configured in your unit file or from your init > script (/etc/{default,sysconfig} etc.). > > The problem is that the configuration for HAProxy and for the processes are in > the same configuration file, and if something is wrong, it won't work anymore. > And the master is supposed to survive a reload with a wrong configuration.
Even without a wrong configuration the important point is that the master must not change its external interfaces (i.e. the socket) if the config changes during a reload, or it really becomes a mess. The typical issue will be that it would then need to consider rebinding across reloads, which means closing and re-opening the socket, and that's terribly bad. First it would prevent from being able to maintain a connection across reloads, second it means that if anything goes wrong during this moment, you definitely lose access to the master's socket with no option to recover it. Willy
